Question

Write any four physiological adaptations in aquatic plants.

Answer 1

The plants that grow in water are known as aquatic plants. Aquatic plants are also known hydrophytes. In order to grow in water, the hydrophytes have evolved morphologically and physiologically.

Complete step by step answer: Adaptation can be defined as features that enable any organisms to live in their specific habitat. These features help the organism to withstand extreme environmental conditions and utilize the environment maximally.
The plants that grow in aquatic environments are known as aquatic plants or hydrophytes. To sustain their life in water, the hydrophytes have evolved to alter various morphological and physiological features compared to their terrestrial counterparts. In this section, we will discuss the physiological adaptation of the hydrophytes.
-Hydrophytes, like all other plants, undergo the process of photosynthesis. However, since most of the plant body is submerged in water, photosynthesis can be done by both stems and leaves of hydrophytes. Oxygen produced during photosynthesis is retained in the plant body in air cavities. This oxygen is used as per requirement.
-Mucilage cells of hydrophytes are very active and produce a lot of mucilage. This mucilage protects the plants from decay.
-Reproduction in aquatic plants is mediated by the vegetative mode. However, if sexual reproduction is carried out, pollination takes place with the help of water.
-Gaseous exchange in hydrophytes occurs only at the surface of the leaves. This is because the leaves have evolved to have stomata only on the upper surfaces.

Additional Information: Hydrophytes or aquatic plants have adapted for growth in water or near water. These plants are light in weight – a trait that helps them to float in water. Based on the type of growth, aquatic plants can be of three types – Floating, Submerged and Emergent.
Floating hydrophytes can either have their roots attached to the soil under water like water lilies, or they can be free floating plants like water cabbages.
Submerged hydrophytes are completely under water plants with roots either attached to the soil like Hydrilla or they float under the water as in Ceratophyllum.
Emergent hydrophytes have a root system attached to the soil under water, but the leaves break the water surface so that the plants are partially in air. Typical examples of emergent plants are Cyperus papyrus and Typha.
The aquatic plants are of great importance to the ecosystem. They act as primary producers of the aquatic ecosystem. Hydrophytes help to uptake the excess Nitrogen and Phosphorus from the water and thereby reduce pollution. These plants also help to regulate nitrogen cycle. They provide a cover for the fishes and release oxygen in water.

Note: Aquatic plants are found in water. They are adapted to sustain life in water. These plants are found in freshwater and also in saline water. Physiological adaptations of aquatic plants enable them to reduce transpiration, store oxygen in air cavities, presence of stomata only at the upper surface of leaves. Aquatic plants provide food for the aquatic animals and also for human beings. They help to regulate nitrogen cycle and reduce water pollution.